mirror of
https://github.com/torvalds/linux.git
synced 2024-11-23 12:42:02 +00:00
Staging: vme: Separate the list of TODOs from the API documentation
This patch moves the API documentation to it's own file and provides a proper list of TODOs. Signed-off-by: Martyn Welch <martyn.welch@gefanuc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Martyn Welch
Greg Kroah-Hartman
parent
3d0f8bc751
commit
bf39f9a5bd
@ -1,388 +1,98 @@
|
||||
VME Device Driver API
|
||||
=====================
|
||||
TODO
|
||||
====
|
||||
|
||||
Driver registration
|
||||
===================
|
||||
API
|
||||
===
|
||||
|
||||
As with other subsystems within the Linux kernel, VME device drivers register
|
||||
with the VME subsystem, typically called from the devices init routine. This is
|
||||
achieved via a call to the follwoing function:
|
||||
DMA Resource Allocation incomplete
|
||||
----------------------------------
|
||||
|
||||
int vme_register_driver (struct vme_driver *driver);
|
||||
The current DMA resource Allocation provides no means of selecting the
|
||||
suitability of a DMA controller based on it's supported modes of operation, as
|
||||
opposed to the resource allocation mechanisms for master and slave windows:
|
||||
|
||||
If driver registration is successful this function returns zero, if an error
|
||||
occurred a negative error code will be returned.
|
||||
struct vme_resource *vme_request_dma(struct device *dev);
|
||||
|
||||
A pointer to a structure of type ???vme_driver??? must be provided to the
|
||||
registration function. The structure is as follows:
|
||||
|
||||
struct vme_driver {
|
||||
struct list_head node;
|
||||
char *name;
|
||||
const struct vme_device_id *bind_table;
|
||||
int (*probe) (struct device *, int, int);
|
||||
int (*remove) (struct device *, int, int);
|
||||
void (*shutdown) (void);
|
||||
struct device_driver driver;
|
||||
};
|
||||
|
||||
At the minimum, the ???.name???, ???.probe??? and ???.bind_table??? elements of this
|
||||
structure should be correctly set. The ???.name??? element is a pointer to a string
|
||||
holding the device driver???s name. The ???.probe??? element should contain a pointer
|
||||
to the probe routine.
|
||||
|
||||
The arguments of the probe routine are as follows:
|
||||
|
||||
probe(struct device *dev, int bus, int slot);
|
||||
|
||||
The ???.bind_table??? is a pointer to an array of type ???vme_device_id???:
|
||||
|
||||
struct vme_device_id {
|
||||
int bus;
|
||||
int slot;
|
||||
};
|
||||
|
||||
Each structure in this array should provide a bus and slot number where the core
|
||||
should probe, using the driver???s probe routine, for a device on the specified
|
||||
VME bus.
|
||||
|
||||
The VME subsystem supports a single VME driver per ???slot???. There are considered
|
||||
to be 32 slots per bus, one for each slot-ID as defined in the ANSI/VITA 1-1994
|
||||
specification and are analogious to the physical slots on the VME backplane.
|
||||
|
||||
A function is also provided to unregister the driver from the VME core and is
|
||||
usually called from the device driver???s exit routine:
|
||||
|
||||
void vme_unregister_driver (struct vme_driver *driver);
|
||||
|
||||
|
||||
Resource management
|
||||
===================
|
||||
|
||||
Once a driver has registered with the VME core the provided probe routine will
|
||||
be called for each of the bus/slot combination that becomes valid as VME buses
|
||||
are themselves registered. The probe routine is passed a pointer to the devices
|
||||
device structure. This pointer should be saved, it will be required for
|
||||
requesting VME resources.
|
||||
|
||||
The driver can request ownership of one or more master windows, slave windows
|
||||
and/or dma channels. Rather than allowing the device driver to request a
|
||||
specific window or DMA channel (which may be used by a different driver) this
|
||||
driver allows a resource to be assigned based on the required attributes of the
|
||||
driver in question:
|
||||
As opposed to:
|
||||
|
||||
struct vme_resource * vme_master_request(struct device *dev,
|
||||
vme_address_t aspace, vme_cycle_t cycle, vme_width_t width);
|
||||
|
||||
struct vme_resource * vme_slave_request(struct device *dev,
|
||||
vme_address_t aspace, vme_cycle_t cycle);
|
||||
The TSI148 can perform, VME-to-PCI, PCI-to-VME, PATTERN-to-VME, PATTERN-to-PCI,
|
||||
VME-to-VME and PCI-to-PCI transfers. The CA91C142 can only provide VME-to-PCI
|
||||
and PCI-to-VME.
|
||||
|
||||
TODO: DMA Resource Allocation incomplete. No attribute based selection.
|
||||
|
||||
struct vme_resource *vme_request_dma(struct device *dev);
|
||||
|
||||
For slave windows these attributes are split into those of type ???vme_address_t???
|
||||
and ???vme_cycle_t???. Master windows add a further set of attributes ???vme_cycle_t???.
|
||||
These attributes are defined as bitmasks and as such any combination of the
|
||||
attributes can be requested for a single window, the core will assign a window
|
||||
that meets the requirements, returning a pointer of type vme_resource that
|
||||
should be used to identify the allocated resource when it is used. If an
|
||||
unallocated window fitting the requirements can not be found a NULL pointer will
|
||||
be returned.
|
||||
|
||||
Functions are also provided to free window allocations once they are no longer
|
||||
required. These functions should be passed the pointer to the resource provided
|
||||
during resource allocation:
|
||||
|
||||
void vme_master_free(struct vme_resource *res);
|
||||
|
||||
void vme_slave_free(struct vme_resource *res);
|
||||
|
||||
void vme_dma_free(struct vme_resource *res);
|
||||
|
||||
|
||||
Master windows
|
||||
==============
|
||||
|
||||
Master windows provide access from the local processor[s] out onto the VME bus.
|
||||
The number of windows available and the available access modes is dependant on
|
||||
the underlying chipset. A window must be configured before it can be used.
|
||||
|
||||
|
||||
Master window configuration
|
||||
---------------------------
|
||||
|
||||
Once a master window has been assigned the following functions can be used to
|
||||
configure it and retrieve the current settings:
|
||||
|
||||
int vme_master_set (struct vme_resource *res, int enabled,
|
||||
unsigned long long base, unsigned long long size,
|
||||
vme_address_t aspace, vme_cycle_t cycle, vme_width_t width);
|
||||
|
||||
int vme_master_get (struct vme_resource *res, int *enabled,
|
||||
unsigned long long *base, unsigned long long *size,
|
||||
vme_address_t *aspace, vme_cycle_t *cycle, vme_width_t *width);
|
||||
|
||||
The address spaces, transfer widths and cycle types are the same as described
|
||||
under resource management, however some of the options are mutually exclusive.
|
||||
For example, only one address space may be specified.
|
||||
|
||||
These functions return 0 on success or an error code should the call fail.
|
||||
Add a mechanism to select a VME controller based on source/target type,
|
||||
required aspace, cycle and width requirements.
|
||||
|
||||
|
||||
Master window broadcast select mask
|
||||
-----------------------------------
|
||||
|
||||
TODO: Add functions to set and get Broadcast Select mask:
|
||||
API currently provides no method to set or get Broadcast Select mask. Suggest
|
||||
somthing like:
|
||||
|
||||
int vme_master_bmsk_set (struct vme_resource *res, int mask);
|
||||
int vme_master_bmsk_get (struct vme_resource *res, int *mask);
|
||||
|
||||
|
||||
Master window access
|
||||
--------------------
|
||||
|
||||
The following functions can be used to read from and write to configured master
|
||||
windows. These functions return the number of bytes copied:
|
||||
|
||||
ssize_t vme_master_read(struct vme_resource *res, void *buf,
|
||||
size_t count, loff_t offset);
|
||||
|
||||
ssize_t vme_master_write(struct vme_resource *res, void *buf,
|
||||
size_t count, loff_t offset);
|
||||
|
||||
In addition to simple reads and writes, a function is provided to do a
|
||||
read-modify-write transaction. This function returns the original value of the
|
||||
VME bus location :
|
||||
|
||||
unsigned int vme_master_rmw (struct vme_resource *res,
|
||||
unsigned int mask, unsigned int compare, unsigned int swap,
|
||||
loff_t offset);
|
||||
|
||||
This functions by reading the offset, applying the mask. If the bits selected in
|
||||
the mask match with the values of the corresponding bits in the compare field,
|
||||
the value of swap is written the specified offset.
|
||||
|
||||
|
||||
Slave windows
|
||||
=============
|
||||
|
||||
Slave windows provide devices on the VME bus access into mapped portions of the
|
||||
local memory. The number of windows available and the access modes that can be
|
||||
used is dependant on the underlying chipset. A window must be configured before
|
||||
it can be used.
|
||||
|
||||
|
||||
Slave window configuration
|
||||
--------------------------
|
||||
|
||||
Once a slave window has been assigned the following functions can be used to
|
||||
configure it and retrieve the current settings:
|
||||
|
||||
int vme_slave_set (struct vme_resource *res, int enabled,
|
||||
unsigned long long base, unsigned long long size,
|
||||
dma_addr_t mem, vme_address_t aspace, vme_cycle_t cycle);
|
||||
|
||||
int vme_slave_get (struct vme_resource *res, int *enabled,
|
||||
unsigned long long *base, unsigned long long *size,
|
||||
dma_addr_t *mem, vme_address_t *aspace, vme_cycle_t *cycle);
|
||||
|
||||
The address spaces, transfer widths and cycle types are the same as described
|
||||
under resource management, however some of the options are mutually exclusive.
|
||||
For example, only one address space may be specified.
|
||||
|
||||
These functions return 0 on success or an error code should the call fail.
|
||||
|
||||
|
||||
Slave window buffer allocation
|
||||
------------------------------
|
||||
|
||||
Functions are provided to allow the user to allocate and free a contiguous
|
||||
buffers which will be accessible by the VME bridge. These functions do not have
|
||||
to be used, other methods can be used to allocate a buffer, though care must be
|
||||
taken to ensure that they are contiguous and accessible by the VME bridge:
|
||||
|
||||
void * vme_alloc_consistent(struct vme_resource *res, size_t size,
|
||||
dma_addr_t *mem);
|
||||
|
||||
void vme_free_consistent(struct vme_resource *res, size_t size,
|
||||
void *virt, dma_addr_t mem);
|
||||
|
||||
|
||||
Slave window access
|
||||
-------------------
|
||||
|
||||
Slave windows map local memory onto the VME bus, the standard methods for
|
||||
accessing memory should be used.
|
||||
|
||||
|
||||
DMA channels
|
||||
============
|
||||
|
||||
The VME DMA transfer provides the ability to run link-list DMA transfers. The
|
||||
API introduces the concept of DMA lists. Each DMA list is a link-list which can
|
||||
be passed to a DMA controller. Multiple lists can be created, extended,
|
||||
executed, reused and destroyed.
|
||||
|
||||
|
||||
List Management
|
||||
---------------
|
||||
|
||||
The following functions are provided to create and destroy DMA lists. Execution
|
||||
of a list will not automatically destroy the list, thus enabling a list to be
|
||||
reused for repetitive tasks:
|
||||
|
||||
struct vme_dma_list *vme_new_dma_list(struct vme_resource *res);
|
||||
|
||||
int vme_dma_list_free(struct vme_dma_list *list);
|
||||
|
||||
|
||||
List Population
|
||||
---------------
|
||||
|
||||
An item can be added to a list using the following function ( the source and
|
||||
destination attributes need to be created before calling this function, this is
|
||||
covered under "Transfer Attributes"):
|
||||
|
||||
int vme_dma_list_add(struct vme_dma_list *list,
|
||||
struct vme_dma_attr *src, struct vme_dma_attr *dest,
|
||||
size_t count);
|
||||
|
||||
|
||||
Transfer Attributes
|
||||
-------------------
|
||||
|
||||
The attributes for the source and destination are handled separately from adding
|
||||
an item to a list. This is due to the diverse attributes required for each type
|
||||
of source and destination. There are functions to create attributes for PCI, VME
|
||||
and pattern sources and destinations (where appropriate):
|
||||
|
||||
Pattern source:
|
||||
|
||||
struct vme_dma_attr *vme_dma_pattern_attribute(u32 pattern,
|
||||
vme_pattern_t type);
|
||||
|
||||
PCI source or destination:
|
||||
|
||||
struct vme_dma_attr *vme_dma_pci_attribute(dma_addr_t mem);
|
||||
|
||||
VME source or destination:
|
||||
|
||||
struct vme_dma_attr *vme_dma_vme_attribute(unsigned long long base,
|
||||
vme_address_t aspace, vme_cycle_t cycle, vme_width_t width);
|
||||
|
||||
The following function should be used to free an attribute:
|
||||
|
||||
void vme_dma_free_attribute(struct vme_dma_attr *attr);
|
||||
|
||||
|
||||
List Execution
|
||||
--------------
|
||||
|
||||
The following function queues a list for execution. The function will return
|
||||
once the list has been executed:
|
||||
|
||||
int vme_dma_list_exec(struct vme_dma_list *list);
|
||||
|
||||
|
||||
Interrupts
|
||||
==========
|
||||
|
||||
The VME API provides functions to attach and detach callbacks to specific VME
|
||||
level and status ID combinations and for the generation of VME interrupts with
|
||||
specific VME level and status IDs.
|
||||
|
||||
|
||||
Attaching Interrupt Handlers
|
||||
----------------------------
|
||||
|
||||
The following functions can be used to attach and free a specific VME level and
|
||||
status ID combination. Any given combination can only be assigned a single
|
||||
callback function. A void pointer parameter is provided, the value of which is
|
||||
passed to the callback function, the use of this pointer is user undefined:
|
||||
|
||||
int vme_request_irq(struct device *dev, int level, int statid,
|
||||
void (*callback)(int, int, void *), void *priv);
|
||||
|
||||
void vme_free_irq(struct device *dev, int level, int statid);
|
||||
|
||||
The callback parameters are as follows. Care must be taken in writing a callback
|
||||
function, callback functions run in interrupt context:
|
||||
|
||||
void callback(int level, int statid, void *priv);
|
||||
|
||||
|
||||
Interrupt Generation
|
||||
--------------------
|
||||
|
||||
The following function can be used to generate a VME interrupt at a given VME
|
||||
level and VME status ID:
|
||||
|
||||
int vme_generate_irq(struct device *dev, int level, int statid);
|
||||
Add optional timeout when waiting for an IACK.
|
||||
|
||||
|
||||
Location monitors
|
||||
=================
|
||||
CR/CSR Buffer
|
||||
-------------
|
||||
|
||||
The VME API provides the following functionality to configure the location
|
||||
monitor.
|
||||
The VME API provides no functions to access the buffer mapped into the CR/CSR
|
||||
space.
|
||||
|
||||
|
||||
Location Monitor Management
|
||||
---------------------------
|
||||
Mailboxes
|
||||
---------
|
||||
|
||||
The following functions are provided to request the use of a block of location
|
||||
monitors and to free them after they are no longer required:
|
||||
|
||||
struct vme_resource * vme_lm_request(struct device *dev);
|
||||
|
||||
void vme_lm_free(struct vme_resource * res);
|
||||
|
||||
Each block may provide a number of location monitors, monitoring adjacent
|
||||
locations. The following function can be used to determine how many locations
|
||||
are provided:
|
||||
|
||||
int vme_lm_count(struct vme_resource * res);
|
||||
Whilst not part of the VME specification, they are provided by a number of
|
||||
chips. They are currently not supported at all by the API.
|
||||
|
||||
|
||||
Location Monitor Configuration
|
||||
------------------------------
|
||||
Core
|
||||
====
|
||||
|
||||
Once a bank of location monitors has been allocated, the following functions
|
||||
are provided to configure the location and mode of the location monitor:
|
||||
- Rename vme_master_resource's "pci_resource" to be bus agnostic.
|
||||
- Improve generic sanity checks (Such as does an offset and size fit within a
|
||||
window and parameter checking).
|
||||
|
||||
int vme_lm_set(struct vme_resource *res, unsigned long long base,
|
||||
vme_address_t aspace, vme_cycle_t cycle);
|
||||
|
||||
int vme_lm_get(struct vme_resource *res, unsigned long long *base,
|
||||
vme_address_t *aspace, vme_cycle_t *cycle);
|
||||
|
||||
|
||||
Location Monitor Use
|
||||
--------------------
|
||||
|
||||
The following functions allow a callback to be attached and detached from each
|
||||
location monitor location. Each location monitor can monitor a number of
|
||||
adjacent locations:
|
||||
|
||||
int vme_lm_attach(struct vme_resource *res, int num,
|
||||
void (*callback)(int));
|
||||
|
||||
int vme_lm_detach(struct vme_resource *res, int num);
|
||||
|
||||
The callback function is declared as follows.
|
||||
|
||||
void callback(int num);
|
||||
|
||||
|
||||
CR/CSR
|
||||
======
|
||||
|
||||
TODO: The VME API needs functions to access the CR/CSR buffer.
|
||||
|
||||
Slot Detection
|
||||
Bridge Support
|
||||
==============
|
||||
|
||||
This function returns the slot ID of the provided bridge.
|
||||
Tempe (tsi148)
|
||||
--------------
|
||||
|
||||
- Driver can currently only support a single bridge.
|
||||
- 2eSST Broadcast mode.
|
||||
- Mailboxes unsupported.
|
||||
- Improve error detection.
|
||||
- Control of prefetch size, threshold.
|
||||
- Arbiter control
|
||||
- Requestor control
|
||||
|
||||
Universe II (ca91c142)
|
||||
----------------------
|
||||
|
||||
- Driver can currently only support a single bridge.
|
||||
- DMA unsupported.
|
||||
- RMW transactions unsupported.
|
||||
- Location Monitors unsupported.
|
||||
- Mailboxes unsupported.
|
||||
- Error Detection.
|
||||
- Control of prefetch size, threshold.
|
||||
- Arbiter control
|
||||
- Requestor control
|
||||
- Slot detection
|
||||
|
||||
Universe I (ca91x042)
|
||||
---------------------
|
||||
|
||||
Currently completely unsupported.
|
||||
|
||||
int vme_slot_get(struct device *dev);
|
||||
|
||||
372
drivers/staging/vme/vme_api.txt
Normal file
372
drivers/staging/vme/vme_api.txt
Normal file
@ -0,0 +1,372 @@
|
||||
VME Device Driver API
|
||||
=====================
|
||||
|
||||
Driver registration
|
||||
===================
|
||||
|
||||
As with other subsystems within the Linux kernel, VME device drivers register
|
||||
with the VME subsystem, typically called from the devices init routine. This is
|
||||
achieved via a call to the follwoing function:
|
||||
|
||||
int vme_register_driver (struct vme_driver *driver);
|
||||
|
||||
If driver registration is successful this function returns zero, if an error
|
||||
occurred a negative error code will be returned.
|
||||
|
||||
A pointer to a structure of type 'vme_driver' must be provided to the
|
||||
registration function. The structure is as follows:
|
||||
|
||||
struct vme_driver {
|
||||
struct list_head node;
|
||||
char *name;
|
||||
const struct vme_device_id *bind_table;
|
||||
int (*probe) (struct device *, int, int);
|
||||
int (*remove) (struct device *, int, int);
|
||||
void (*shutdown) (void);
|
||||
struct device_driver driver;
|
||||
};
|
||||
|
||||
At the minimum, the '.name', '.probe' and '.bind_table' elements of this
|
||||
structure should be correctly set. The '.name' element is a pointer to a string
|
||||
holding the device driver's name. The '.probe' element should contain a pointer
|
||||
to the probe routine.
|
||||
|
||||
The arguments of the probe routine are as follows:
|
||||
|
||||
probe(struct device *dev, int bus, int slot);
|
||||
|
||||
The '.bind_table' is a pointer to an array of type 'vme_device_id':
|
||||
|
||||
struct vme_device_id {
|
||||
int bus;
|
||||
int slot;
|
||||
};
|
||||
|
||||
Each structure in this array should provide a bus and slot number where the core
|
||||
should probe, using the driver's probe routine, for a device on the specified
|
||||
VME bus.
|
||||
|
||||
The VME subsystem supports a single VME driver per 'slot'. There are considered
|
||||
to be 32 slots per bus, one for each slot-ID as defined in the ANSI/VITA 1-1994
|
||||
specification and are analogious to the physical slots on the VME backplane.
|
||||
|
||||
A function is also provided to unregister the driver from the VME core and is
|
||||
usually called from the device driver's exit routine:
|
||||
|
||||
void vme_unregister_driver (struct vme_driver *driver);
|
||||
|
||||
|
||||
Resource management
|
||||
===================
|
||||
|
||||
Once a driver has registered with the VME core the provided probe routine will
|
||||
be called for each of the bus/slot combination that becomes valid as VME buses
|
||||
are themselves registered. The probe routine is passed a pointer to the devices
|
||||
device structure. This pointer should be saved, it will be required for
|
||||
requesting VME resources.
|
||||
|
||||
The driver can request ownership of one or more master windows, slave windows
|
||||
and/or dma channels. Rather than allowing the device driver to request a
|
||||
specific window or DMA channel (which may be used by a different driver) this
|
||||
driver allows a resource to be assigned based on the required attributes of the
|
||||
driver in question:
|
||||
|
||||
struct vme_resource * vme_master_request(struct device *dev,
|
||||
vme_address_t aspace, vme_cycle_t cycle, vme_width_t width);
|
||||
|
||||
struct vme_resource * vme_slave_request(struct device *dev,
|
||||
vme_address_t aspace, vme_cycle_t cycle);
|
||||
|
||||
struct vme_resource *vme_request_dma(struct device *dev);
|
||||
|
||||
For slave windows these attributes are split into those of type 'vme_address_t'
|
||||
and 'vme_cycle_t'. Master windows add a further set of attributes 'vme_cycle_t'.
|
||||
These attributes are defined as bitmasks and as such any combination of the
|
||||
attributes can be requested for a single window, the core will assign a window
|
||||
that meets the requirements, returning a pointer of type vme_resource that
|
||||
should be used to identify the allocated resource when it is used. If an
|
||||
unallocated window fitting the requirements can not be found a NULL pointer will
|
||||
be returned.
|
||||
|
||||
Functions are also provided to free window allocations once they are no longer
|
||||
required. These functions should be passed the pointer to the resource provided
|
||||
during resource allocation:
|
||||
|
||||
void vme_master_free(struct vme_resource *res);
|
||||
|
||||
void vme_slave_free(struct vme_resource *res);
|
||||
|
||||
void vme_dma_free(struct vme_resource *res);
|
||||
|
||||
|
||||
Master windows
|
||||
==============
|
||||
|
||||
Master windows provide access from the local processor[s] out onto the VME bus.
|
||||
The number of windows available and the available access modes is dependant on
|
||||
the underlying chipset. A window must be configured before it can be used.
|
||||
|
||||
|
||||
Master window configuration
|
||||
---------------------------
|
||||
|
||||
Once a master window has been assigned the following functions can be used to
|
||||
configure it and retrieve the current settings:
|
||||
|
||||
int vme_master_set (struct vme_resource *res, int enabled,
|
||||
unsigned long long base, unsigned long long size,
|
||||
vme_address_t aspace, vme_cycle_t cycle, vme_width_t width);
|
||||
|
||||
int vme_master_get (struct vme_resource *res, int *enabled,
|
||||
unsigned long long *base, unsigned long long *size,
|
||||
vme_address_t *aspace, vme_cycle_t *cycle, vme_width_t *width);
|
||||
|
||||
The address spaces, transfer widths and cycle types are the same as described
|
||||
under resource management, however some of the options are mutually exclusive.
|
||||
For example, only one address space may be specified.
|
||||
|
||||
These functions return 0 on success or an error code should the call fail.
|
||||
|
||||
|
||||
Master window access
|
||||
--------------------
|
||||
|
||||
The following functions can be used to read from and write to configured master
|
||||
windows. These functions return the number of bytes copied:
|
||||
|
||||
ssize_t vme_master_read(struct vme_resource *res, void *buf,
|
||||
size_t count, loff_t offset);
|
||||
|
||||
ssize_t vme_master_write(struct vme_resource *res, void *buf,
|
||||
size_t count, loff_t offset);
|
||||
|
||||
In addition to simple reads and writes, a function is provided to do a
|
||||
read-modify-write transaction. This function returns the original value of the
|
||||
VME bus location :
|
||||
|
||||
unsigned int vme_master_rmw (struct vme_resource *res,
|
||||
unsigned int mask, unsigned int compare, unsigned int swap,
|
||||
loff_t offset);
|
||||
|
||||
This functions by reading the offset, applying the mask. If the bits selected in
|
||||
the mask match with the values of the corresponding bits in the compare field,
|
||||
the value of swap is written the specified offset.
|
||||
|
||||
|
||||
Slave windows
|
||||
=============
|
||||
|
||||
Slave windows provide devices on the VME bus access into mapped portions of the
|
||||
local memory. The number of windows available and the access modes that can be
|
||||
used is dependant on the underlying chipset. A window must be configured before
|
||||
it can be used.
|
||||
|
||||
|
||||
Slave window configuration
|
||||
--------------------------
|
||||
|
||||
Once a slave window has been assigned the following functions can be used to
|
||||
configure it and retrieve the current settings:
|
||||
|
||||
int vme_slave_set (struct vme_resource *res, int enabled,
|
||||
unsigned long long base, unsigned long long size,
|
||||
dma_addr_t mem, vme_address_t aspace, vme_cycle_t cycle);
|
||||
|
||||
int vme_slave_get (struct vme_resource *res, int *enabled,
|
||||
unsigned long long *base, unsigned long long *size,
|
||||
dma_addr_t *mem, vme_address_t *aspace, vme_cycle_t *cycle);
|
||||
|
||||
The address spaces, transfer widths and cycle types are the same as described
|
||||
under resource management, however some of the options are mutually exclusive.
|
||||
For example, only one address space may be specified.
|
||||
|
||||
These functions return 0 on success or an error code should the call fail.
|
||||
|
||||
|
||||
Slave window buffer allocation
|
||||
------------------------------
|
||||
|
||||
Functions are provided to allow the user to allocate and free a contiguous
|
||||
buffers which will be accessible by the VME bridge. These functions do not have
|
||||
to be used, other methods can be used to allocate a buffer, though care must be
|
||||
taken to ensure that they are contiguous and accessible by the VME bridge:
|
||||
|
||||
void * vme_alloc_consistent(struct vme_resource *res, size_t size,
|
||||
dma_addr_t *mem);
|
||||
|
||||
void vme_free_consistent(struct vme_resource *res, size_t size,
|
||||
void *virt, dma_addr_t mem);
|
||||
|
||||
|
||||
Slave window access
|
||||
-------------------
|
||||
|
||||
Slave windows map local memory onto the VME bus, the standard methods for
|
||||
accessing memory should be used.
|
||||
|
||||
|
||||
DMA channels
|
||||
============
|
||||
|
||||
The VME DMA transfer provides the ability to run link-list DMA transfers. The
|
||||
API introduces the concept of DMA lists. Each DMA list is a link-list which can
|
||||
be passed to a DMA controller. Multiple lists can be created, extended,
|
||||
executed, reused and destroyed.
|
||||
|
||||
|
||||
List Management
|
||||
---------------
|
||||
|
||||
The following functions are provided to create and destroy DMA lists. Execution
|
||||
of a list will not automatically destroy the list, thus enabling a list to be
|
||||
reused for repetitive tasks:
|
||||
|
||||
struct vme_dma_list *vme_new_dma_list(struct vme_resource *res);
|
||||
|
||||
int vme_dma_list_free(struct vme_dma_list *list);
|
||||
|
||||
|
||||
List Population
|
||||
---------------
|
||||
|
||||
An item can be added to a list using the following function ( the source and
|
||||
destination attributes need to be created before calling this function, this is
|
||||
covered under "Transfer Attributes"):
|
||||
|
||||
int vme_dma_list_add(struct vme_dma_list *list,
|
||||
struct vme_dma_attr *src, struct vme_dma_attr *dest,
|
||||
size_t count);
|
||||
|
||||
|
||||
Transfer Attributes
|
||||
-------------------
|
||||
|
||||
The attributes for the source and destination are handled separately from adding
|
||||
an item to a list. This is due to the diverse attributes required for each type
|
||||
of source and destination. There are functions to create attributes for PCI, VME
|
||||
and pattern sources and destinations (where appropriate):
|
||||
|
||||
Pattern source:
|
||||
|
||||
struct vme_dma_attr *vme_dma_pattern_attribute(u32 pattern,
|
||||
vme_pattern_t type);
|
||||
|
||||
PCI source or destination:
|
||||
|
||||
struct vme_dma_attr *vme_dma_pci_attribute(dma_addr_t mem);
|
||||
|
||||
VME source or destination:
|
||||
|
||||
struct vme_dma_attr *vme_dma_vme_attribute(unsigned long long base,
|
||||
vme_address_t aspace, vme_cycle_t cycle, vme_width_t width);
|
||||
|
||||
The following function should be used to free an attribute:
|
||||
|
||||
void vme_dma_free_attribute(struct vme_dma_attr *attr);
|
||||
|
||||
|
||||
List Execution
|
||||
--------------
|
||||
|
||||
The following function queues a list for execution. The function will return
|
||||
once the list has been executed:
|
||||
|
||||
int vme_dma_list_exec(struct vme_dma_list *list);
|
||||
|
||||
|
||||
Interrupts
|
||||
==========
|
||||
|
||||
The VME API provides functions to attach and detach callbacks to specific VME
|
||||
level and status ID combinations and for the generation of VME interrupts with
|
||||
specific VME level and status IDs.
|
||||
|
||||
|
||||
Attaching Interrupt Handlers
|
||||
----------------------------
|
||||
|
||||
The following functions can be used to attach and free a specific VME level and
|
||||
status ID combination. Any given combination can only be assigned a single
|
||||
callback function. A void pointer parameter is provided, the value of which is
|
||||
passed to the callback function, the use of this pointer is user undefined:
|
||||
|
||||
int vme_request_irq(struct device *dev, int level, int statid,
|
||||
void (*callback)(int, int, void *), void *priv);
|
||||
|
||||
void vme_free_irq(struct device *dev, int level, int statid);
|
||||
|
||||
The callback parameters are as follows. Care must be taken in writing a callback
|
||||
function, callback functions run in interrupt context:
|
||||
|
||||
void callback(int level, int statid, void *priv);
|
||||
|
||||
|
||||
Interrupt Generation
|
||||
--------------------
|
||||
|
||||
The following function can be used to generate a VME interrupt at a given VME
|
||||
level and VME status ID:
|
||||
|
||||
int vme_generate_irq(struct device *dev, int level, int statid);
|
||||
|
||||
|
||||
Location monitors
|
||||
=================
|
||||
|
||||
The VME API provides the following functionality to configure the location
|
||||
monitor.
|
||||
|
||||
|
||||
Location Monitor Management
|
||||
---------------------------
|
||||
|
||||
The following functions are provided to request the use of a block of location
|
||||
monitors and to free them after they are no longer required:
|
||||
|
||||
struct vme_resource * vme_lm_request(struct device *dev);
|
||||
|
||||
void vme_lm_free(struct vme_resource * res);
|
||||
|
||||
Each block may provide a number of location monitors, monitoring adjacent
|
||||
locations. The following function can be used to determine how many locations
|
||||
are provided:
|
||||
|
||||
int vme_lm_count(struct vme_resource * res);
|
||||
|
||||
|
||||
Location Monitor Configuration
|
||||
------------------------------
|
||||
|
||||
Once a bank of location monitors has been allocated, the following functions
|
||||
are provided to configure the location and mode of the location monitor:
|
||||
|
||||
int vme_lm_set(struct vme_resource *res, unsigned long long base,
|
||||
vme_address_t aspace, vme_cycle_t cycle);
|
||||
|
||||
int vme_lm_get(struct vme_resource *res, unsigned long long *base,
|
||||
vme_address_t *aspace, vme_cycle_t *cycle);
|
||||
|
||||
|
||||
Location Monitor Use
|
||||
--------------------
|
||||
|
||||
The following functions allow a callback to be attached and detached from each
|
||||
location monitor location. Each location monitor can monitor a number of
|
||||
adjacent locations:
|
||||
|
||||
int vme_lm_attach(struct vme_resource *res, int num,
|
||||
void (*callback)(int));
|
||||
|
||||
int vme_lm_detach(struct vme_resource *res, int num);
|
||||
|
||||
The callback function is declared as follows.
|
||||
|
||||
void callback(int num);
|
||||
|
||||
|
||||
Slot Detection
|
||||
==============
|
||||
|
||||
This function returns the slot ID of the provided bridge.
|
||||
|
||||
int vme_slot_get(struct device *dev);
|
||||
Loading…
Reference in New Issue
Block a user